GODFOX UNIVERSITY 

Founded in 2002 



Rules Design 2  Metric Time and Distance 

In the first chapter we examined miles per hour and looked at ways to convert these into inches on the wargame table. In this section we will look at kilometers per hour. The following table shows kilometers per hour and the actual meters per hour and meters per minute that may be moved. The column at the end rounds up the meters per minute to drop all fractions and have easier numbers to work with. While some may prefer multiples of the prime number 17 for esoteric reasons, multiples of 18 are divisible by 2, 3, 6 and 9. (The rounded value at 1 kph actually equals 1.077984 kph. At 30 kph it equals 32.393521 kph, so the distortion is already about 8% at this speed.)
With this information it is very easy to relate time to distance moved. We will use the rounded numbers from the table above. In 1 minute, a unit with a movement rate of 1 kilometer per hour can move 18 meters. A unit with a movement rate of 3 kilometers per hour can move 54 meters. We now have another practical and realistic time to movement relationship. How do we use these numbers on a wargame table? If a centimeter equals 1 meter in your wargame rules (1/100 scale), a unit that can move at a rate of 3 kilometers per hour (54 meters per turn) can move 54 centimeters in one turn. (Keep in mind that we are working with a 1 minute time frame.)
Probably very few rules use a scale of 1 centimeter equals 1 meter, so we will want to be able to change the scale. We will also want to be able to change the amount of time per turn. This is a relatively straightforward process and a few examples will illustrate this:
In the same manner that we converted yards and miles per hour we can create a time and distance scale where a unit can move one centimeter per turn for every kilometer per hour of its movement rate. The following table provides the details for a number of different scales.
Based on the above table, if a wargamer using 1/285 scale vehicles sets the length of the turn at 10 seconds (15.26 rounded down) a tank with a speed of 40 kph will be able to move 40 centimeters per turn. Keep in mind that terrain has not been factored in, so these are maximum speeds. Comparing miles and kilometers At some point a wargame designer may want to compare the movement rates of miles per hour with those of kilometers per hour. This might be particularly true in the postWorld War Two era, when the speeds of American tanks are usually given in miles per hour and those of European nations are given in kilometers per hour. How far does a tank with a cross country speed of 20 miles per hour move in terms of kilometers per hour? The following table provides the corresponding kilometers per hour, meters per hour and meters per minute for various speeds in miles per hour. The column at the end rounds up the meters per minute to drop all fractions and have easier numbers to work with. (The rounded value at 1 mph actually equals 1.0683654 mph. At 30 mph it equals 30.2050963 mph, less than a quarter of a mph over our rounded number, so the distortion is not too great.)
The following table provides the corresponding miles per hour, yards per hour and yards per minute for various speeds in kilometers per hour. The column at the end rounds down the yards per minute to drop all fractions and have easier numbers to work with. (The rounded value at 1 kph actually equals 0.98973607 kph. At 30 kph it equals 29.6920821 kph, less than a third of a kph under our rounded number, so the distortion is not too great.)



